Telephone system



Sept. 8, 1931. A. TRADUP 132L993 TELEPHONE SYSTEM Filed Nov. 21 1929 2Sheets-Sheet 1 //VVENTO/P A. 7k40up ATTORNEY Sept. 8, 1931. A. TRADUPTELEPHONE SYSTEM 2 Sheets-Sheet 2 Filed Nov. 21. 1929 Patented Sept. 8,1931 LSZLQQB UNITED STATESd FATEFZNT @FFICE ALBERT TRADUP, OF WESTENGLEWOOD, NEW JERSEY, ASSIGN'QR TO AMERICAN TELE- PHONE AND TELEGRAPHCOMPANY, A OOEPORATTON OF NEW YORK TELEPHONE SYSTEM Application filedNovember 21, 1929.

house line extends to a bank of switches for outgoing service to anumber of service lines such as those to the superintendent, to thejanitor, to the secretarial desk and to the service entrances. There isalso provided a separate bank of switches through which the house linesmay be reached from the service lines. With this arrangement a callermay establish a connection from a service entrance to a given apartmentand 2a the occupant of the apartment may thereupon establish a newconnection which will result in the operation of a door lock controllingmagnet and a contiguous signal to give notice to the caller that thedoor may a; be opened. Upon the opening of the door a signal will betransmitted back to the occupant of the called apartment to let suchoccupant know that the caller has entered. There is further provided asecretarial desk be in which each central oflice line has an appearance.Each such line terminates thereat in a circuit so arranged that thesecretary may gain access thereto only in answering an incoming call andthen only when the -15 circuit has been so conditioned upon the expressorders of an occupant of an apartment.

A feature of the invention is the combination of the direct centralofiice line to an apartment and its branch appearing in the Isecretarial desk in such a circuit arrangement that the secretarythereat may gain access to it only in response to incoming calls and theswitching arrangement whereby the occupant of the apartment mayestablish a connection through local means to the said secretarial deskto deliver orders for the performance of absentee service.

Anot ier feature of the invention resides in the means for performingdoor opening 1'1 service over the local telephone switching Serial No.408,780.

arrangements, together with the means for returning a signal to theparty who has established a door opening connection upon the opening ofthe door The drawings consist of two sheets, the first containing Fig. 1which is a schematic representation of the apartment house telephonesystem containing the present invention, and the second containing Figs.2, 3 and 4. Fig. 2 is a circuit diagram showing the manner in which acentral office line terminates in the secretarial desk. Fig. 3 is acircuitdiagram illustrating the door opening circuit and Fig. 4 is acircuit diagram representing the apartment sub-station switchingarrangement.

Each apartment is provided with a telephone instrument 1. and aswitching arrangement 2. A central oilice line 3 entering the apartmentterminates in the switching arrangement 2 and a signaling device 4. Ahouse line 5 also terminates in the switching arrangement 2 and asignaling arrangement 6. The house line at its other end terminates inthe bank of a line finder switch 7 by means of which the line may beextended to a connector 8 and from thence to the secretarial desk overtrunk 9 or to any one of the service telephones 10, 11 or 12. Thus linefinder switch 7 and connector 8 form one switching arrangement wherebyoutgoing service from the apartment may be had.

From the service telephones '10, '11 and 12, connection may be extendedthrough the line finder switch 13 and thence through the selector switch14 and the connector switch 15 to the various apartment lines such as 5and 16 and also to the service lines including the trunk 9 to thesecretarial desk 17 The secretarial desk is provided with single endedcord circuits indicated at 18 so that while the secretary may attend toall incoming calls, she may do no switching.

Each central office line such as 3 terminates'in the secretarial desk ina circuit such as shown in Fig. 2. In this case a dummy plug 19 ofinsulating material is shown as inserted in the jack 20 wherebyconnection between the contacts 21 and 22 of the jack 20 is opened. If,while the dummy plug 19 is so inserted in the jack 20, ringing currentshould be applied to the two conductors 23 and 24 of this central oiiiceline, it will find no circuit, since the path through the lower windingof relay 26 is open.

Should the operator remove the dummy plug 19 and insert a cord circuitplug into jack 20, she would be unable to get a connection to thecentral office because both the tip and the ring conductors from thejack are opened at the contacts of relay 25.

It is therefore only wnen the dummy plug 19 is removed and when ringingcurrent is applied to conductors 23 and 24: that the operator will beable to get in on the connection. At such a time ringing current appliedto conductor 24 will flow through contacts 21 and 22, lower winding ofrelay 26, condenser 27, and thence over ring ductor 24. Relay 26 willbecome operated and will lock through its upper winding to groundsupplied over the lower outer armature and back contact of relay 25.When the operator inserts the plug in jack 20, ground will be connectedthrough the sleeve of jack 20 to operate relay 25 throu h the upperarmature and front contact of relay 26. Thereupon relay 25 locks overits up per outer armature and front contact and relay 26 is deenergizedthrough the opening of the lower outer armature and back con tact ofrelay 26. During the energization of relay 26, the calling signal 28 isoperated.

In the operation of this system, a caller will manipulate the dial onthe telephone 12 at the service entrance to actuate line finder switch13, selector 1d and connector 15 to establish a connection to a desiredapartment. The occupant there answering the telephone and learning thata caller is at the service entrance, will first hang up and thenestablish a new connection over line finder switch 7 and connector 8 toline 29 terminating in a door lock magnet 30.

In accordance with the well known operation of standard apparatus (refrring now to Fig. the conductors 31, 32 and respectively represent thetip, ring and sleeve conductors of the li -e 29 coming from connectorswitch 8. Upon the establishment of the said connection to line 29, aground will be placed on conductor 33 which will operate relay 3%. Relay34 through its lower armature, closes a local circuit for operating adoor lock magnet 30. Through its upper armature, relay closes anotherlocal circuit to operate a signal 35 such as a buzzer placed contiguousto the door lock magnet 80. Thus, the caller, hearing the signal, willknow that the door may be opened.

Durnig the existence of this connection, ringmg current will be appliedto conductors 31 and 32 and 1n accordance with the usual practice, aringing tone will be transmitted to the telephone of the calling party.\Vhen the door is opened by the caller, contacts 36 and 37 will beclosed, whereupon a bridge including a resistance 38 sufficiently low invalue to trip the machine ringing 1n the connector will be establishedacross the tip and ring conductors 31 and 32. "When the machine ringingin the connector is thus tripped, the ringing tone to the callingsubscriber will cease and thus give a signal that the caller has openedthe door.

Should a subscriber wish to have the secretary take care of incomingcalls during his absence, he may, by the proper manipulation of the key2 and the dial on his telephone, establish a connection over line finderswitch 7 and connector 8 to trunk 9, terminating in any usual manner inthe secretarial desk. The secretary thereat will answer the call andupon instructions will remove the dummy plug 19 from the correspondingjack associated with the central oflice line 3. Therefore, during theabsence of the subscriber at substation 1, the secretary may answerincoming calls and record the information gathered in this way for thefuture benefit of the subscriber. The secretary may at a later periodestablish a connection over trunk 9 through line finder switch 13,selector 14 and connector 15 to an apartment to impart such informationas she has gathered during the absence of the subscriber.

lVhat is claimed is:

1. In an apartment house telephone sys tem, an apartment substation, acentral office line extending directly to said apartment substation, ahouse telephone line extending from said apartment substation, means forswitching said apartment substation from one to the other of said lines,house switching means for extending said house telephone line, servicelines accessible to said house telephone line via said house switchingmeans, a secretarial desk, a line from said house switching means tosaid secretarial desk included in said service lines, a branch of saidcentral oi'hce line terminating at said secretarial desk in a circuitarrangement whereby said central office line is accessible thereat onlyin response to incoming calls, and means under control of a secretaryupon instructions delivered over said house telephone line for renderingsaid central oiiice line inaccessible thereat even in response toincoming calls.

2. In an apartment house telephone system, an apartment substation, acentral office line extendin directly to said apartment substation, ahouse telephone line extending from said apartment substation, means forswitching said apartment substation from one to the other of said lines,house service lines, house switching means for extending said housetelephone line to said house service line, a separate house switchingmeans ofor extending said house service lines to said house telephoneline, a secretarial desk, at line from said house switching means tosaid secretarial desk included in said house servic lines, a branch ofsaid central oilice line terminating at said secretarial desk in acircuit arrangement whereby said central office line is accessiblethereat only in response to incoming calls, and means under control of asecretary upon instructions delivered over said house telephone line forrendering said central office line inaccessible thereat even in responseto incoming calls.

3. In an apartment house telephone system, apartment lines, servicelines, a switching means for extending said apartment lines to saidservice lines, a separate switching means for extending said servicelines to said apartment lines, a door, a door lock controlling magnet,said magnet being operable over one of said service lines upon theestablishment of a connection from an apartment line thereto over saidswitching means, means included in said switching means responsive tothe establishment of such connection for transmitting a signal back oversaid established connection, and means controlled by said door forstopping the operation of said signaling means.

4. In an apartment house telephone system, apartment lines, servicelines, automatic switches for extending said apartment lines to saidservice lines, other automatic switches for extending said service linesto said apartment lines, a door, a door lock controlling magnet, saidmagnet being operable over one of said service lines upon theestablishment of a connection from an apartment line thereto over saidautomatic switches, means included in said switching means responsive tothe establishment of such connection for transmitting a signal back oversaid established connection, and means controlled by said door forstopping the operation of said signaling means.

5. In an electrical service system, a telephone system, a door, a doorlock controlling magnet, means for establishing a connection to and foroperating said magnet for said telephone system, means included in saidfirst means responsive to the establishment of such connection fortransmitting a signal back over said established connection, and meanscontrolled by said door for stopping the operation of said signalingmeans.

6. In an electrical service system, a telephone system, a door, a doorlock controlling magnet, a signal contiguous to said door, means forestablishing a connection to and for simultaneously operating saidmagnet and said signal, means included in said first means responsive tothe establishment of such connection for transmitting a signal back oversaid established connection, and means controlled by said door forstopping the operation of said last signaling means.

7. In an electrical service system, a dial telephone system, a door, adoor lock con.- trolling magnet, means responsive to coded dial impulsesfor establishing a connection to and for operating said magnet, meansincluded in said first means responsive to the establishment of suchconnection for transmitting a signal back over said establishedconnection, and means controlled by said door for stopping the operationof said signaling means.

8. In an electrical service system, a telephone system including aplurality of telephone substations, a door lock controlling magnetcommon to said substations, a signal contiguous to said magnet, andmeans for establishing a connection from any one of said substations toand for simultaneously operating said magnet and said signal over saidtelephone system.

In testimony whereof, I have signed in name to this specification this19th day of November, 1929.

ALBERT TRADUP.

